In a known type of yarn store, a winding arm serves to wind weft yarn onto the periphery of a stationary drum. During intervals between picks, a portion of the yarn leading from the periphery of the drum to an air jet or other loom picking instrumentality is held or clamped adjacent the drum and turns of yarn are accumulated on the drum. At the time of a pick, the clamp is released and there is made available to the picking jet a total length equal to the length of weft yarn to be picked into the shed of the loom.
Japanese utility model publication No. 7265/86 discloses a store in which a lever disposed outside the drum presses the weft yarn on to the drum periphery during the times when yarn is not required to be drawn off the drum. The mechanical drive of the lever makes it necessary to have a separate mounting of the drive shaft, so that additional space is required in the vicinity of the periphery of the drum. The end of the lever strikes the drum directly, and so delicate weft yarn may be damaged when it is clamped